1. Field of the Invention
The present invention relates to a print control device, a memory control method, a print control method, and a memory medium for allowing image data to be generated from intermediate data and printed by a printing unit.
2. Related Backqround Art
Conventionally, the printing apparatuses of the type in which the print image creating position within a page of data can not be determined in the order of receiving input data (e.g., page description language) involved creating (rasterizing) visual image for the print output after receiving input data of one page.
In many printing apparatuses of this type, because if the print image to be actually printed is directly received for processing, received data will become very large, input data for each object such as "character data" or "circle" is received for processing.
Such printing apparatuses of the type in which input data is formed (rasterized) into print data at the same time when input data is received had a problem that print image data is significantly larger than input data with higher resolution of printing apparatuses, and a memory capacity amounting to the maximum output size is always needed, for which a large capacity memory device (raster buffer) dedicated for the output print image is required, resulting in the increased cost of printing apparatuses. Herein, a memory device (RAM) within a printing apparatus is allocated to an intermediate buffer for memorizing intermediate data as hereinafter described as a print assurance memory area, a raster buffer for memorizing print image data rasterized from the intermediate data, or a cache buffer as hereinafter described, in addition to a reception buffer for temporarily memorizing input data received.
Hence, there were some printing apparatuses of the type in which received input data is stored in an intermediate buffer within an internal memory (RAM) in the format before forming the print image (intermediate data), and after storage of one page, collectively rasterized to form the print image, but they had a problem that when intermediate data of one page has a size exceeding a storage capacity of the intermediate buffer provided in the printing apparatus (memory overflow), that intermediate data of its page could not be processed.
Also, the printing apparatuses of the type in which, regarding data such as e.g., character data for which it takes much time to form print image, data once formed into a print image is saved in a cache buffer of the internal memory (RAM), and then the print image within the cache buffer is used for the same print data, thereby shortening the total processing time, had a problem that the memory device (RAM) having large enough capacity must be prepared to shorten the processing time, because its efficiency can be determined by the storage capacity of memory device (RAM).
Also, the printing apparatuses which perform the printing on both sides of a recording sheet as recording medium involved forming (rasterizing) the print image and outputting it visually, after completion of receiving the input data of necessary pages, even if the page order of input data received and the page order of print image to be printed are not matched owing to the way of storing the recording sheets which have been printed.
Those above-mentioned printing apparatuses, which form print image from input data at the same time when receiving the input data, require a memory device (RAM) having a raster buffer of large capacity, because the amount of image data for the print image is significantly larger than the amount of input data as the resolution of printing apparatuses increases. Hence, especially the printing apparatuses having a perfect printing feature had a problem that the cost of the apparatus may be increased.
Thus, a printing apparatus has been proposed in which input data received is stored in a memory device in the state before forming the print image (intermediate data), and the print image is formed after completion of storing the intermediate data of one page. That is, since input data is converted into intermediate data which is memorized in an intermediate buffer, more input data can be processed for printing within a limited memory capacity.
Also, a printing apparatus having a form overlay processing function is well known in which when a part of input data is the same for every page, such input data (form data) of the same content is preregistered in memory in the format of intermediate data, and the preregistered form data is added to the received input data for the printing, for that part of the same content for every page. Herein, the form data includes data such as external character, LOGO, or the ruled line.
Also, in the above-mentioned printing apparatus having the form overlay processing function, for example, when the image forming order is problematical of input data which is formed (rasterized) visually at the same position, the print data (form data) to effect the form overlay processing is often formed (rasterized) into visual image before received input data, seeing that the form overlay processing function is more frequently used for the frame or LOGO.
However, when data indicating the form overlay processing for the printing page is not provided at the top of page, there was a problem that the printed result was quite different from expected one, such as the form data not formed or the form data printed later, for example, if the capacity of memory device becomes insufficient.